Wat Ban Rai in Korat is one of my favorite temples in Thailand. Perhaps only surpassed by Wat Rong Khun in Chiang Rai, Wat Ban Rai is a fantastic temple in the shape of an elephant with a huge variety of statues and art work. While this is certainly an active Buddhist temple, the influence from Hindu and even Christian religions is unmistakable. The outside of the temple looks like a Hells Angels-Hindu-Christian-Greco-Roman mash-up with Hindu looking gods being portrayed as Poseidon and possibly even Zeus. Inside Wat Ban Rai are beautiful paintings and modern Buddhist art. Work you way to the top of the temple and you get a view of the surround countryside along with some large statues of the Buddha himself along with a monk. I was not there at night, but the temple is lit up and quite stunning in the photos I have seen.
Visiting Wat Ban Rai is not difficult. There are many tour buses to the temple and Korat (Nakhon Ratchasima) is not too far from Bangkok. You should easily be able to visit the temple in one day. Weekends and Thai holidays will be crowded since the temple is popular with the Thai.